Hydrofining of lubricating oil fractions



y 1961 D. H. WILLSON ET AL 2,985,586

HYDROFINING OF LUBRICATING OIL FRACTIONS Filed NOV. 26, 1958 HYDROGEN x}ADDITlVE 3O 38 HYDROGEN REACTION 39 SULFIDE ZONE 3| 34 IB- TLLUBRICATING 7 4| on. ,4,2O SEPARATION 35 33 HEATER ZONE 2 54 36FRACTION/AL LUBSIIEATING DISTILLATION FRACTION ZONE aun gzns 2| EFFECTOF WEIGHT PER CENT SULFUR AND HYDROFINING TEMPERATURE ON AVERAGE BEARINGWEIGHT LOSS AND PISTON SKIRT VARNISH FOR PANHANDLE ISO-NEUTRAL OIL l I Il 5.4 l 0.4

5.0 0.0 O .04 .08 .l2 .l6 .20 .24 .26 .32

WEIGHT PER CENT SULFUR DAN H. WILLSON, GEORGE R. L. SHEPHERD,

AT OR United States Patent HYDROFINING OF LUBRICATING OIL ERA'CTIONSFiled Nov. 26, 1958, Ser. No. 781,419

- 7 Claims. (Cl. 208264) The present invention is directed tohydrofining of lubricating oil fractions. More particularly, theinvention is concerned with treating a lubricating oil fraction in thepresence of hydrogen to form an improved lubricant. In its more specificaspects, the invention is concerned with the formation of a lubricatingoil which contains sulfur. Y e

The present invention is directed to the production of improvedlubricating oil in which a lubricating oil fraction is hydrofined in thepresence of a sulfur-resistant catalyst at 'a-tem'perature within therange from about 400 to about 650 F. under a pressure within the rangefrom about 200 to about 1,000 pounds per square inch and at a spacevelocity within the range from about 1 to; Y

about 10 v./v./hr. in the presence of sufficient free by:drogen-containing gas to provide from about 50 to about 5,000 standardcubic feet of hydrogen per barrel of the lubricating oil fraction, thehydrogen-containing gas also containing from about 5% to about 95% byvolume of hydrogen sulfide to form a product containing sulfur and ofimproved lubricating quality.

The feed stock employed in the present invention is a lubricating oilfraction which may boil in the'range from about 800 to about 1,200" F.and ordinarily will comprise a fraction of crude petroleum. Higherboiling fractions may also be used. Such lubricating oil fractions areknown as neutral oils, light motor oils, medium motor oils, and brightstocks. It is contemplated that the lubricating oil fraction employed inthe present invention may suitably be a solvent ralfinate of alubricating oil fraction obtained from crude petroleum. Examples of thecrude petroleum from which the lubricating oil fraction may be obtainedare the Gulf Coastal crudes, Panhandle crudes, Pennsylvania type crudeoils, and California crude oils and the like.

The invention is suitably practiced with a suitable sulfur-resistantcatalyst, of which many are known to the,

art. As examples of suitable catalysts are the oxides and sulfides ofmetals such as vanadium, chromium, manganese, iron, cobalt, nickel,molybdenum, tungsten, and the like. Specific examples of such catalystsare cobalt molybdate, nickel-tungsten sulfide, cobalt sulfide,molybdenum sulfide, molybdenum oxide, nickel sulfide, tin sulfide, andthe like. The catalysts are preferably employed on a support or asuitable carrier such as alumina, magnesia, silica, zirconia, spinels,and the like. The catalyst may be employed as a fixed bed catalyst, inthe form of a fluidized bed, or as a slurry in the lubricating oil, or

in any other suitable manner.

The present invention is suitably conducted in the lpresence ofhydrogen, and an amount of hydrogen within the range from about 50 toabout 5,000 standard cubic 'feet per barrel is employed. A preferredamount of hydrogen is from about 65 to about 500 standard cubic feet perbarrel. The hydrogen for the operation is provided by charging ahydrogen-containing gas to the catalyst along with the feed stock. Thehydrogen-containing gas may be added from an extraneous source and maybe pure hydrogen or may comprise a mixture of hydro- 2,985,586 PatentedMay 23, 1961 ice gen and gaseous material such as light hydrocarbons.For example, gaseous material from the operation may provide at least apart of the hydrogen-containing gas as a source of the hydrogen for thereaction.

The amount of hydrogen sulfide which is added with the hydrogen iswithin the range from about 5% to about by volume of the total gas witha preferred range from about 20% to about 70% by volume based on thetotal gas. In the present invention the hydrogen sulfide may largely beprovided from an extraneous source since ordinarily the amount ofhydrogen sulfide provided in a hydrofining operation is not suflicientfor best results. However, recycle of tail gas may provide suflicienthydrogen sulfide build up.

The temperatures employed in the practice of the present invention maysuitably range from about 400 to about 650 F. with desirable resultsbeing obtained at about 500 F. A preferred temperature range is fromabout 475 to about 575 F.

Pressures may suitably range from about 200 to about 1,000 pounds persquare inch with good results being obtained at about 750 pounds persquare inch. A preferred range is from about 400 to about 800 pounds persquare inch.

The space velocity may range from about 1 to about 10 volumes of feedper volume of catalyst per hour with a, preferred space velocity fromabout 3 to about 5 In accordance with the present invention, improvedresults are obtained in that the present invention provides alubricating oil product which .contains sulfur in an amount greater thanthat usually present in a hydrofined lubricating oil product. Thepresence of sulfur confers unusual properties on the lubricating oil inthat in the present invention the response of the product to lubricatingoil additives and inhibitors is enhanced. In other words, for a givenamount of a lubricating oil additive or inhibitor, a greater response ishad with the product of the present invention that with a conventionallyhydrofined product. Furthermore, the product hydrofined according tothis invention performs more satisfactorily than conventionallyhydrofined products without inhibitors. This means that with the presentinvention, amounts of additives can be reduced and yet obtain beneficialresults.

The present invention will be further illustrated by reference to thedrawing in which:

Fig. 1 is a flow diagram of a preferred mode of practicing theinvention, and

Fig. 2 is a graphical presentation of data showing the elfect of sulfurand hydrofining temperature on bearing weight loss and piston skirtvarnish for a Panhandle neutral oil.

Referring now to the drawing and particularly to Fig. 1, numeral 11designates a charge line by way of which a lubricating oil fraction isintroduced into the systemtion only, a neutral or light motor oil ischarged. Introduced intoline, 11 by line 12 is a hydrogen-containing gasin which hydrogen sulfide is suitably added by way of line 13 controlledbyvalve 14. v The mixture of hydrogen, hydrogen sulfide, and lubricatingoil is suitably introduced into a heater 15' provided with a heatingcoil 16 and with burners such as gas burners 17, by way of which thetemperature of the mixture is raised to a temperature within the rangegiven before. The heated mixture, under the conditions setout herein, isdischarged from heater '15 by line 18 and introduced thereby into areaction zone 19 containing a bed of catalyst 20 such as cobaltmolybdate. Under the conditions for the practice of this invention, thelubricating oil fraction is suitably hydrofined and a product is formedwhich is withdrawn by line 21 34, 35, and 36 for withdrawal and recoveryof the lubricating oil fractions. Line 37 is provided for discharge ofheavier fractions which may be of bright stock quality. It will beunderstood, however, that when one of the and discharged thereby into aseparation zone 22, which components of the total lubricating oilfraction is charged,

is of suitable capacity to provide a residence time for separation ofnormally gaseous products from the liquid products, the gaseous productsbeing withdrawn from separation zone 22 by line 23 for recycling to line12 zone 28 may be used only to remove light ends and to recover thedesired productthrough line 37 with lines 31, 32, and 33 being closed.While the inhibitor may be added directly to the distilled product, theinhibitor by branch line 24 controlled by valve 25. This recycled ispreferably added to the final blended motor oil.

gas provides at least a portion of the hydrogen and may provide aportion of the hydrogen sulfide for the process. A portion of the gasmay suitably be discharged from line 23 by manipulation of valve 26.

Since the product of this operation has enhanced response to lubricatingoil additives or inhibitors, provision is made for adding a lubricatingoil additive by way of manifold 38 which connects into lines 31, 32, and33 and When the total lubricating oil fraction is charged, the intowhich flow is controlled by way of valves 39, 40,

liquid products from Zone 22 are withdrawn therefrom by line 27 andintroduced into a fractional distillation zone 28, which is shown as asingle fractional distillation tower but which may be a plurality offractional distiland 41 as may be desired. Where a selected oil such asneutral oilis hydrofined and withdrawn by line 37, inhibitor may beadded thereto as desired.

If the recycled gas does notprovide suflicient hydro lation towers, eachequipped with all auxiliary apparatus gen, this may be provided from anextraneous source by usually incident to a modern fractionaldistillation tower. Thus, zone 28 is provided with suitable internal,vaporliquid contacting means, cooling and condensing means, means forinducing reflux and the like, not shown. Zone opening valve 42 in line12. v

In order to illustrate the present invention'further, a number ofhydrofining runs were made employing Panhandle l50-neutral raffinate,Panhandle light motor oil 28 is equipped with a heating means 29,illustrated by rafiinate, and Panhandle 150-'X bright stock raffinate asteam coil, for adjusting temperature and pressure for distillation ofthe liquid product. Line is provided for removal of light fractionsboiling above lubricating oil and lines 3-1, 32, and 33 controlled,respectively, by valves using 10 to 20 mesh cobalt molybdate as acatalyst.

The following table I sets out the several conditions and the productinspections resulting from the hydrofining operations.

TABLE I Hydrofimng conditions and product mspectzons Type of CatalystCobalt Molybdate, 10-20 Mesh Run Number Feed 465 Feed 474 476 476 477478 498 499 Feed; 7 527- 528 3 529 Feed Stocks Panhandle ISO-NeutralRaflinate' Reactor Temperasure, F 475 .Q 500 500 475 475 550 575 550Reactor Pressure, P s i Q 300 750 750 700. 700 700 750 750 Feed Rate,v./v./Hr 3. 1 3. 2 3.1 3. 2 3. 2 3. 2 4. 8 3.2 Total Gas Rate, s.c.f./Hr27 24 26 26 24 30 23 23 Hydrogen Sulfide Injected, Volume Percent ofTotal G 11 5 11 1O 5 22 68 79 Hydrogen Gas:

Volume Percent of Total Gas 89 95 89 90 95 78 32 21 S.c.t./Bb1. Feed 342337 345 340 339 339 71 72 Product Inspections:

Gravity, API 33. 2 33. 3 32. 4 32. 6 32. 6. 32. 6 32. 6 32. 7 32. 7 33-1Flash, 0.0. F 400 415 430 425 425 425 42 410 420 410 Viscosity,SSU/IONF--- 139 6 137.7 148.0 146 3 146 1 146.5 146.4 146 2 146 4 139.7Viscosity, SSU/210 F-.. 42 9 42.8 43.4 43 2 43 3 43.3 43.2. 43 3 42.8Color, Tag Roblnson 9% 19% 9% 19% 18% 19 18% 19% 19% 22% Color Hold TagRoblnso 17% 9% 19 18% 18 19% 19 21 Pour, F..- 15 15 15 25 20 20 25 30 2501011 16 24 24 30 26 28 28 42 44 28 Sulfur, Wt. 11 O 21 0.20 0.27 0 14 016 0 20 0.19 0 10 0 14 0.16 Con. Carbon, Wt. pe ent 0 01 0.05 0.01 O 010 01 0 01 0.01 0 01 0 00 0.00 Aniline Point, F 224 222 220 221 221 221221 221 221 222 Type of Catalyst Cobalt Molybdate, 10-20 Mesh Run NumberFeed 479 480 481 382 494 495 "500 501 Feed Stocks. Panhandle Light MotorRaflinate Reactor Temperature, F 500 500 425 425 575 "575 575 625Reactor Pressure, P st Q 700 700 700 700 750 750i. .750 750 Feed Rate,v./v./hr-- 3.1 3.1 3 1 3.1 3.1 3.1 4.7 4. 7 Total Gas Rate, s.c.f./hr 2426 26 25 28 23 24 Hydrogen Sulfide Injected, Volume Percent of TotalGas... 5 11 12 6 68 70 Hydrogen Gas:

Volume Percent of Total Gas. 88 94' .50 40 32 30 S.c.f./Bb1. F 347 349346 349 212 212 72 72 Product Inspections:

Gravity, API 30.7 30.9 30 9 30 7 30.8 31 0 81 0 31 0 91.0 Flash, F 465460 470 470 465 455 450 455 455 Viscosity, SSU/ F" 324 316 318 323 322311 311 312 306 Viscosity, SSU/210 F 54.6 54.2 54 3 54 7 54.6 54.0 54 154 1 53.7 Color, Tag Robinson... 5 13 12 10% 10 17% 17 '14 Color HoldTag Robinson 4% 12 11 /4 9% 9% 17% 17% 14% 12% Pour, F 15 25 25 20 2035; 5 35 Cloud, F .20 26 28 22 I 26- 45 4o 45 Sulfur, Wt. Percent 0.320.22 0.24 0. 33 0. 33 0.14 0.16 0118, 0.11 Con. Carbon, Wt. Percen 0.040.04 0.04 0,02 0.04 0.02 0.02. 0.02 0.03 Aniline Polnt, F 231 232 232.232 231, 234 234 233 234 TABLE I-Contiiiued Cobalt Molybdate, 10-20 MeshType oi Catalyst Run Number Feed 483 y 484 485 486 496 497 Feed 521 522525 526 Feed Stocks Panhandle 150-X Bright Stock Raflinate ReactorTemperature, 9F 500 50 550 600 575 575 450 500 500 450 Reactor Pressure,P.s.i.g 700 700 700 700 750 750 750 750 750 Feed Rate, v./v./l1r 3. l .03. 3.0 2. 9 3. l 3. 2 3. 2 3. 2 Total Gas Rate, Sci/Hr--- 24 26 29 29 3614 14 20 20 Hydrogen Sulfide Injected, Volume Percent of Total Gm 11 2222 61 76 0 0 28 Hydrogen Gas: 7

Volume Percent of Total Gas. 95 89 78 78 39 24 100 100 72 70 S.o.l./Bbl.Feed. 349 353 362 356 224 80 207 206 206 206 Product Inspections: 3 a

Gravity, API 27. 4 27. 3 27. 3 27. 5 27.7 27.4 27. 4 27. 5 27. 5 27.527. 5 27. 5 Flash, 0. 0. F 595 590 590 570 570 565 580 580 675 570 575Viscosity, 85171100" 2, 410 2, 362 2, 422 2, 324 2, 258 2, 350 2, 333 2,120 2, 094 2, 064 2, 090 2, 113 Viscosity, SSU/210 F 157. 2, 155. 7 155.9 154. 4 151. 3 153. 7' 154. 7 145. 0 a 3. 8 142.2 143. 8 144. 7 Color,Tag Robinson 2% 4 4% 4% 5% +9+ +9+ 7 r 2% 3 4% 5% 4 Color Hold TagRobins 2 3 3% 3% 4% +9+ 8, 6 7 2 -1%- 3% 4% 3% our, F 20 20 30 15 15 1510 15 Cloud, F 22 18 18 52 26 28 31 31 29 Sulfur, Wt. Percent 0. 47 0.45 0. 46 .0. 42 0. 29 0. 42 0. 43 0. 48 0. 47 0. 36 0. 45 0. 47 Con.Carbon, Wt. Percent. 0. 64 O. 0.72 0. 59 0.56 0. 68 0. 74 0. 64 0. 70'0.73 0.63 0.65 Aniline Point, F 261 261 264 264 264 262 262 260 7 260 v260 260 260 Selected products from the several runs illustrated in TableI were then subjected to a 36-hour L-4 Chevrolet engine test and theseproducts were compared with similar products produced by clay contactingonly and with lubricating oils hydrofined in the absence of hy sulfidein the enteringgas. In Table II the test results in Panhandle 150neutral oils of Table I are presented.

- that samples SX-4803 and 4804 where the present invention wasalsopracticed'had higher sulfur contents than the conventionally hydrofinedoils of SX-4400. Sample SX-5479, on the other hand, had a'piston skirtdrogen 30 varnish which was substantially the same as; that of theclay-contacted oil and had a lower average'bearing weight loss than anyof the oils and yet the sulfur content of TABLE 11 36-hour, L-4Chevrolet engine test results on Panhandle 150-neutral Sample NumberSX-4174 SX-4400 SIC-4401 SX-4577 SX-4505 SX-4803 Hydrofinlng 'Iemp., F575 575 575 475 500 Hydrofiner Run Number" 413 '413 41 3 465 474 Percentin Entering Gas; 0 0 0 11 5 Wt. Percent Sulfur (Before Additive)- 0.220.04 0.04 0.04 0. 20 0.14 Additive 0 0 0. 5% 0. 7% 0 0 1 L-1060 111-1060 36-Hr;, L-4Results: I

Piston Skirts SR1 (Southwest Research Institute) 8.8 6.1 6 1 9.1 6.8 6.8Varnish, Total 46.3 40.1 40. 6 46.6 43.8 42. 3 Sludge, Total 47. 5 46. 048.0 8.0 46.5 45.0 Avg. BWL, gulls 0.728 2.854 1. 233 0. 015 1. 032 1.627 Used Oil Data (36Hrs.): I

' Percent Viscosity Increase SSU/l00 F 23.3 30. 9 3.12 46. l

8ample Number SX-4804 SX-5150 SK-4962 SX-5479 SX-4805 SX-4806Hydrofining Temp., F 550 550 575 500 475 550 Hydrofiner Run Number.--478 499 498 528 476 478 Percent H25 in Entering Gas" 22 68 68 66 10 22Wt Percent Sulfur (Before Add 0. l0 0. 18 0.14 0 27 i 0. 0. 10

tive 0 0 0 0 0. 5 0. 5%

- 1 A 93O 1 A-93O 36-Hr., L-4 Results:

Piston Skirts SRI (Southwest Research Institute); 5. 4 7. 7 8. 3 8. 5 8.2 0. 5 Varnish, Total. 39. 4 43. 7 45.8 46.0 45. 7 46.0 Sludge, TotaL-44. 0 45. 0 47. 5 47. 5 47. 5 48. 0 Avg. BWL, gms 1.997 0.820 1. 632 0.458 0.092 0.020 Used Oil Data (36-Hrs): Percent Viscosity Increase,SSU/100 F--- 53. 7 38.3 31. 2 18 7 15. 7 15. 7

l Zinc dialkyl dithiophospha'te. 4 Clay contacted.

Referring to Table II, 'it will be seen that sample No. 'SX-4962'has apiston skirt varnish of nearly equal quality to that of S X-4l74, Wherethe oil was finished by clay contacting. In this rating, the higher thevalue, the better the rating. Furthermore, SX-4962 is of better qualitythan the conventionally hydrofined oil as represented by SX-4400. It isto be noted that the sulfur content of the conventionally hydrofined oilof SX-4400. It is to be noted that the sulfur content of sample SX-4962is greater than the sulfur content of the conventionally hydrofined oilof SX-4400. It to .be further noted ent invention than where a greateramount of additive was used in a conventionally hydrofined product. Itmay be seen from the data of Table II that at the preferred hydrofiningtemperature, a lesser amount may be sufficient to give the same qualityas was obtained with 0.5% as in SX-4806. Hence, the additiverequirements might be reduced anywhere from about 50% to about 85% bythe practice of the present invention.

- obtained with a conventional hydrofined product. By

providing hydrogen sulfide in the inlet gas, it is possible tosubstantially improve the quality of the lubricating TABLE III 36 hour,L-4 Chvrolet engine test results on Panhandle LMO 1 Sample NumberSEQ-3922 SX'-3923 821-3924 SX-4963 SX-4019 SDI- 4145 Hydrofining Temp.,F 625 425 425 625 "425 HydrofinerRun Number (oliay 351 383 481 351 383tacted Percent H18 in Entering Gas-.. 0 12 0 Wt. Percent Sulfur (beforeadditive) 0.29 0.02 0. 0. 34 0.02 0 2 Additive 0 0 0 0 +0- 5% +0 111-1060 1 11-1060 36-Hr., L-4Results: Piston Skirts, SRI 9.3 9.0 9.2 9.19.5 a1 47.3 47.0 47.2 47.1 47.5

1 Zinc dialkyl dithiophosphate.

In order to show the improved results further, referring to Table III,it will be seen that oils of a quality substantially identical withclay-contacted produced oils are obtained. Comparing SX-3922 withSX-4963, which represents the present invention, the product of thepresent invention was substantially the same as the clay-contacted oilcomparing the clay-contacted oil, as represented by SX-3922, and the oilproduced in accordance with this v operation, SX-4963, with SX-3924,which is the conventionally produced oil, it will be seen that thepractice of the present invention produces an oil which has a lowerbearing weight loss and a higher sulfur content.

Referring to Fig. 2, the sulfur content of the Panhandle ISO-neutral isplotted against piston skirt varnish rating and average bearing weightloss. These data show that the bearing weight loss decreases as sulfurcontent of the hydrofined product increases and that the piston skirt'varnish rating is dependent on the sulfur content and the hydrofiningtemperature. By way of explanation as stated supra, a low bearing Weightloss and a high piston skirt varnish rating are desirable. V

From these results, it is clear that the present invention givessubstantially improved results over conventional hydrofining operationswhere hydrogen sulfide is not employed in the hydrogen-containing gas. I

The lubricating oil additives employed in the practice of the presentinvention may suitably include the wellknown lubricating oilantioxidants and corrosion inhibitors, such as described by Kalichevskyand Kobe in their work Petroleum Refining with Chemicals, ElsevierPublishing Co., New York, 1956, in Tables 159 and 166. Examples of suchcompounds are barium salt of alkyl phenol sulfide, cadmium, copper, orlead oleate or naphthenate, copper compounds, calcium salt of alkylphenol sulfides or disulfides, metal alkyl xanthates, alkaline earth andalkaline metal salts of mahogany acids, aluminum diphenate, aluminumnaphthenate, bivalent metal sulfonates, and the like. It is contemplatedthat these additives and those mentioned by Kalichevsky et al. supra maybe employed inthe practice of the present invention.

These several antioxidants and corrosion inhibitors are given by way ofillustration and not by Way of limitation.

'Inthe practice of the present invention, the sulfur content of thehydrofined product is greater than that which comprises hydrofining alubricating oil fraetion'in the presence of a sulfur-resistant catalystat a temperature within the rangefrorn about 400 toabout-575 F. under apressure within the range from about 200 to about 1,000 pounds persquare inch and at a space velocity within the range from about '1 toabout;-1 0 v./v./hr. in the presence of sufficient freehydrogen-containing gas to provide from about 50 to about 5,000 standardcubic feet of hydrogen per barrel of said lubricating oil fraction, saidgas also containing from about 5% to about 95% by volume of hydrogensulfide, toforrn a product-containing an increased amount ofjsulfur andof improved lubricating quality over conventionally hydrofined oils.

2. A method in accordance with claim 1 in which the catalyst is cobaltmolybdate. V

3. A method in accordance withfclai'rn 11 in which an inhibitor is addedto-the product. 1

4. A method in accordance with'claim l in which the lubricating oilfraction is obtained'from Panhandle crude.

5. A method for producing an improved lubricatingoil which compriseshydrofining a lubricating oil fraction in V the presence of cobaltmolybdate at af temperature within the range from about 475 to about,575F. under a pressure within the range ffrom about 400'toabout'800 poundsper square inch and at a space velocity within the range from about 3 toabout .5. v./v./hr. in the presence of sufiicient freehydrogen-containing .gas to provide from about 65 to about 500 standardcubic feet of hydrogen per barrel of'said lubricating oil fraction, saidgas also containing trom about 20 .to about by volume of hydrogensulfide to form'a product containing sulfur an increased amount of andofimproved lubricating quality over conventionally hydrofined oils.

6. An improved lubricatingoil containing sulfur formed by hydrofining alubricating oil fraction in the presence of a sulfur resistant catalystat a temperature within the range from about 400 to'about 575 F. under apressure within the range from about 200 to about 1,000pounds per squareinch and at a space velocity within the range from about .1 to about 10v./v./hr. in the presence of sufiicient free hydrogen-containing gas toprovide from about 50 to about 500 standard cubicfeet of hydrogen perbarrel of said lubricating oil fraction, said .gas also containing fromabout 5% to about 95% by volume of hydrogen sulfide. v

7. An improved lubricating oil in accordance with claim 6 in which thelubricating oil fraction is derived from Panhandle crude.

References Cited in the file of this patent UNITED STATES PATENTS StrangSept. 11, 1951 Hoffman et a1. May 12, 1953

1. A METHOD FOR PRODUCING AN IMPROVED LUBRICATING OIL WHICH COMPRISESHYDROFININH A LIBRICATING OIL FRACTION IN THE PRESENCE OF ASULFUR-RESISTANT CATALYST AT A TEMPERATURE WITHIN THE RANGE FROM ABOUT400* TO ABOUT 575*F. UNDER A PRESSURE WITHIN THE RANGE FROM ABOUT 200 TOABOUT 1,000 POUNDS PER SQUARE INCH AND AT SPARE VELOCITY WITHIN THERANGE FROM ABLUT 1 TO ANOUT 10V./V./HR. IN THE PRESENCE OF SUFFICENTFREE HYDROGEN-CONTAINING GAS TO PROVIDED FROM ABOUT 50 TO ABOUT 5,000STANDARD CUBIC FEET OF HYDROGEN PER BARREL OF SAID LIBRICATING OILFRACTION, SAID GAS ALSO CONTAINING FROM ABOUT 5% TO ABOUT 95% BY VOLUMEOF HYDROGEN SULFIDE, TO FORM A PRODUCT CONTAINING AN INCREASED AMOUNT OFSULFUR AND OF IMPROVED LUBRICATING QUALITY OVER CONVENTIONALLYHYDROFINED OILS.